Conventional bookcases are made to be a one-piece structure which includes a top board, a bottom board, two sidewalls and one or two front doors. All of the parts are fixedly by nails (for wood boards) or by way of welding (for metal boards). The conventional bookcases are not convenient to be transported and occupy a lot of space which increases cost for the manufactures. As shown in FIGS. 9 and 10, a conventional foldable bookcase 80 includes a front frame 81, a rear board 83, a foldable top board 85 and a foldable bottom board 86 both are connected between the front frame 81 and the rear board 83, two sidewalls 82 and two doors 84. Each of the top board 85 and the bottom board 86 is composed of two parts 87 which are pivotably connected to each other by pivots 871 and can be folded along the connection side located at a center of the top board 85 and the bottom board 86. The other side opposite to the connection side of each of the top board 85 and the bottom board 86 are pivotably connected to the front frame 81 and the rear board 83 by connection pieces 872. The two ends of each of the parts 87 include L-shaped engaging plates 88 which are connected to holes 821 of the sidewalls 82. Therefore, the bookcase 80 can be folded into a compact size by folding the top board 85 and the bottom board 86.
Nevertheless, the folding line, i.e. the connection side is exposed and can be seen from outside of the bookcase 80 and the engaging plates 88 need extra machining processes to be made on the parts 27 of the top board 85 and the bottom board 86. The engaging plates 88 protrude from the parts 27 and exposed so that the bookcase 80 cannot meet requirements of aesthetic purposes.
The present invention intends to provide a foldable bookcase wherein the top board, the bottom board and the two sidewalls can be folded relative to the front frame. Besides, the bookcase of the present invention has no folding lines and engaging plats can be seen from outside of the bookcase.